positive ground fuzz face

[numpty]

the fuzz face i built won't work work in my effects chain, but will on its own or at the beginning. Is that because its positve ground or is it out of phase. Does it need buffers or converting to negative ground?

[John Lyons]

Positive ground pedals will not work with negative ground pedals.
You either need to use a separate power supply for said pedal (with the +/- switched) or use a battery only.

You can also build a MAX1044 circuit into the Positive ground pedal and then it will run off the regular PS that you already use.
Take a look at gaussmarkov.net for the MAX1044 circuit.

John

[petemoore]

the fuzz face i built won't work work in my effects chain, but will on its own or at the beginning.
 Not much to go on...
  Is that because its positve ground or is it out of phase.
 You probably won't notice a phase inversion unless it's out of phase with something else...for that you'd need two amps or a mixer etc.
Does it need buffers or converting to negative ground?
I can't tell what you actually have wired there, so I can't say anything much about where a problem might be.
If FF has + to ground, and - to ground on other effects are connected from the same power supply it is direct shorted, perhaps that's what's happening.

[roknjohn]

Numpty,

What I did to get around this was use jacks with plastic bushings and a separate power supply (or a battery would work as well). I used the jacks because every once in a while the pedal would shift around and make contact with a negative ground pedal, causing it to cut out. This way the entire case is isolated from the power supply. It seemed to work work in my case anyway. I can put it anywhere in my signal chain without power problems.

[numpty]

Thanks for your replies. It has its own separate battery supply and will only work in conjuction with my modifi3ed wah with buffers. In between other effects its audible but with little output. It's the original circuit built on perfboard. Sound as it should with tested ac128 .

[petemoore]

  FF has impedance matching issues with many wahs [like the ones with no buffer], and some other effects with less than higher input impedance, if a buffer cures it, that's probably it.
  My FF sounds gakk into my wah, without anything between them to better match impedance.